Cirrocumulus castellanus (Cc cas) - CCH 1953
(Section 2.3.2.2.3)Cirrocumulus where some elements are vertically developed in the form of small turrets, rising from a common horizontal base. The apparent width of the turrets is always less than 1°, when observed at an angle of more than 30° above the horizon. Castellanus develops due to instability at that level.
